scholarly journals Modeling the Metabolic Reductions of a Passive Back-Support Exoskeleton

2022 ◽  
Author(s):  
Mohammad Mehdi Alemi ◽  
Athulya A. Simon ◽  
Jack Geissinger ◽  
Alan T. Asbeck
Keyword(s):  
Oxygen Consumption ◽  
Cost Model ◽  
Metabolic Cost ◽  
Experimental Results ◽  
Prediction Errors ◽  
Expenditure Data ◽  
Metabolic Difference ◽  
The Mean ◽  
Metabolic Expenditure ◽  
Study Designs

Despite several attempts to quantify the metabolic savings resulting from the use of passive back-support exoskeletons (BSEs), no study has modeled the metabolic change while wearing an exoskeleton during lifting. The objectives of this study were to: 1) quantify the metabolic reductions due to the VT-Lowe's exoskeleton during lifting; and 2) provide a comprehensive model to estimate the metabolic reductions from using a passive BSE. In this study, 15 healthy adults (13M, 2F) of ages 20 to 34 years (mean=25.33, SD=4.43) performed repeated freestyle lifting and lowering of an empty box and a box with 20% of their bodyweight. Oxygen consumption and metabolic expenditure data were collected. A model for metabolic expenditure was developed and fitted with the experimental data of two prior studies and the without-exoskeleton experimental results. The metabolic cost model was then modified to reflect the effect of the exoskeleton. The experimental results revealed that VT-Lowe's exoskeleton significantly lowered the oxygen consumption by ~9% for an empty box and 8% for a 20% bodyweight box, which corresponds to a net metabolic cost reduction of ~12% and ~9%, respectively. The mean metabolic difference (i.e., without-exo minus with-exo) and the 95% confidence interval were 0.36 and (0.2-0.52) [Watts/kg] for 0% bodyweight, and 0.43 and (0.18-0.69) [Watts/kg] for 20% bodyweight. Our modeling predictions for with-exoskeleton conditions were precise, with absolute freestyle prediction errors of <2.1%. The model developed in this study can be modified based on different study designs, and can assist researchers in enhancing designs of future lifting exoskeletons.

The effects of intensity on the energetics of brief locomotor activity

1999 ◽  
Vol 202 (22) ◽  
pp. 3081-3087 ◽  
Author(s):  
E.J. Baker ◽  
T.T. Gleeson
Keyword(s):  
Oxygen Consumption ◽  
Recovery Period ◽  
Metabolic Cost ◽  
Exercise Duration ◽  
Companion Paper ◽  
Energetic Cost ◽  
Unit Distance ◽  
Metabolic Expenditure ◽  
Intensity Of Exercise ◽  
Inclusive Analysis

The energetic costs associated with locomotion are often estimated only from the energy expended during activity and do not include the costs incurred during recovery. For some types of locomotion, this method overlooks important aspects of the metabolic costs incurred as a result of the activity. These estimates for energetic cost have also been predicted from long-duration, low-intensity activities that do not necessarily reflect all the behavior patterns utilized by animals in nature. We have investigated the effects of different activity intensities on the metabolic expenditure (per unit distance traveled) associated with brief exercise, and offer a more inclusive analysis of how the energetics of short-duration activities might be analyzed to estimate the costs to the animal. Mice ran on a treadmill for 15 or 60 s at 25 %, 50 % or 100 % of maximum aerobic speed (MAS) while enclosed in an open-flow respirometry system. Following the run, each mouse was allowed to recover while remaining enclosed in the respirometry chamber. Excess exercise oxygen consumption (EEOC), the excess volume of oxygen consumed during the exercise period, increased with the duration and increased linearly with the intensity of exercise. In contrast, the volume of oxygen consumed during the recovery period, or excess post-exercise oxygen consumption (EPOC), was independent of exercise intensity and duration and accounted for more than 90 % of the total metabolic cost. The net cost of activity (C(act)), calculated by summing EEOC and EPOC and then dividing by the distance run, increased as both activity duration and intensity decreased. The values for C(act) ranged from 553 ml O(2)g(−)(1)km(−)(1) for a 15 s run at 25 % MAS to 43 ml O(2)g(−)(1)km(−)(1) for a 60 s run at 100 % MAS. Combining these data with data from a companion paper, we conclude (1) that EPOC is independent of both the duration and intensity of activity when exercise duration is brief in mice, (2) that EPOC accounts for a majority of the oxygen consumed as a result of the activity when exercise durations are short, and (3) that animals can minimize their energy expenditure per unit distance by running faster for a longer period.

scholarly journals Contour Detection for Fibre of Preserved Szechuan Pickle Based on Dilated Convolution

2019 ◽  
Vol 9 (13) ◽  
pp. 2684 ◽  
Author(s):  
Hongyang Li ◽  
Lizhuang Liu ◽  
Zhenqi Han ◽  
Dan Zhao
Keyword(s):  
Edge Detection ◽  
State Of The Art ◽  
Contour Detection ◽  
Experimental Results ◽  
Contour Method ◽  
Class Differences ◽  
Dilated Convolution ◽  
The Mean ◽  
Art Performance

Peeling fibre is an indispensable process in the production of preserved Szechuan pickle, the accuracy of which can significantly influence the quality of the products, and thus the contour method of fibre detection, as a core algorithm of the automatic peeling device, is studied. The fibre contour is a kind of non-salient contour, characterized by big intra-class differences and small inter-class differences, meaning that the feature of the contour is not discriminative. The method called dilated-holistically-nested edge detection (Dilated-HED) is proposed to detect the fibre contour, which is built based on the HED network and dilated convolution. The experimental results for our dataset show that the Pixel Accuracy (PA) is 99.52% and the Mean Intersection over Union (MIoU) is 49.99%, achieving state-of-the-art performance.

Vibratory Feeding by Nonsinusoidal Vibration—Optimum Wave Form

1985 ◽  
Vol 107 (2) ◽  
pp. 188-195 ◽  
Author(s):  
S. Okabe ◽  
Y. Kamiya ◽  
K. Tsujikado ◽  
Y. Yokoyama
Keyword(s):  
Experimental Results ◽  
Wave Form ◽  
Velocity Wave ◽  
The Mean ◽  
Straight Lines ◽  
Vibratory Conveyor ◽  
Theoretical Results ◽  
Vibratory Feeding

This paper presents the conveying velocity on a vibratory conveyor whose track is vibrated by nonsinusoidal vibration. The velocity wave form of the vibrating track is approximated by six straight lines, and five distortion factors of the wave form are defined. Considering the modes of motion of the particle, the mean conveying velocity is calculated for various conditions. Referring to these results, the optimum wave form is clarified analytically. The theoretical results show that the mean conveying velocity is considerably larger than that of ordinary feeders if the proper conveying conditions are chosen. The theoretical results are confirmed by experimental results.

scholarly journals Energy cost and muscular activity required for propulsion during walking

2003 ◽  
Vol 94 (5) ◽  
pp. 1766-1772 ◽  
Author(s):  
Jinger S. Gottschall ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Muscular Activity ◽  
Metabolic Cost ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Horizontal Force ◽  
Normal Walking ◽  
The Mean ◽  
The Cost ◽  
Muscle Actions

We reasoned that with an optimal aiding horizontal force, the reduction in metabolic rate would reflect the cost of generating propulsive forces during normal walking. Furthermore, the reductions in ankle extensor electromyographic (EMG) activity would indicate the propulsive muscle actions. We applied horizontal forces at the waist, ranging from 15% body weight aiding to 15% body weight impeding, while subjects walked at 1.25 m/s. With an aiding horizontal force of 10% body weight, 1) the net metabolic cost of walking decreased to a minimum of 53% of normal walking, 2) the mean EMG of the medial gastrocnemius (MG) during the propulsive phase decreased to 59% of the normal walking magnitude, and yet 3) the mean EMG of the soleus (Sol) did not decrease significantly. Our data indicate that generating horizontal propulsive forces constitutes nearly half of the metabolic cost of normal walking. Additionally, it appears that the MG plays an important role in forward propulsion, whereas the Sol does not.

scholarly journals A Location Map Reduced Reversible Data Hiding Method Using Prediction Error Modification

2012 ◽  
Vol 6-7 ◽  
pp. 428-433
Author(s):  
Yan Wei Li ◽  
Mei Chen Wu ◽  
Tung Shou Chen ◽  
Wien Hong
Keyword(s):  
Image Quality ◽  
Data Hiding ◽  
Prediction Error ◽  
Reversible Data Hiding ◽  
Experimental Results ◽  
Cover Image ◽  
Prediction Errors ◽  
Secret Data ◽  
Location Map ◽  
Comparable Image Quality

We propose a reversible data hiding technique to improve Hong and Chen’s (2010) method. Hong and Chen divide the cover image into pixel group, and use reference pixels to predict other pixel values. Data are then embedded by modifying the prediction errors. However, when solving the overflow and underflow problems, they employ a location map to record the position of saturated pixels, and these pixels will not be used to carry data. In their method, if the image has a plenty of saturated pixels, the payload is decreased significantly because a lot of saturated pixels will not joint the embedment. We improve Hong and Chen’s method such that the saturated pixels can be used to carry data. The positions of these saturated pixels are then recorded in a location map, and the location map is embedded together with the secret data. The experimental results illustrate that the proposed method has better payload, will providing a comparable image quality.

The Swimming of Nymphon Gracile (Pycnogonida): The Energetics of Swimming at Constant Depth

1977 ◽  
Vol 71 (1) ◽  
pp. 205-211
Author(s):  
ELFED MORGAN
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Tidal Cycle ◽  
Active Phase ◽  
Constant Depth ◽  
Total Carbohydrate ◽  
Drag Forces ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Tide Period

1. The mechanical power required by Nymphon for swimming at constant depth has been calculated from drag forces acting on the legs. For an adult male this was found to be 3.4 W kg. Only about 60% of this is used to support the animal's weight in water. 2. The metabolic rate fluctuates spontaneously over a tidal cycle, being greatest during the ebb-tide period. The mean rate of oxygen consumption during the animals least active phase was found to be about 0.1 μlO2 mg−1 h−1. 3. The total carbohydrate and lipid immediately available for combustion have been estimated at 4.64 and 16 μg/mg wet wt respectively. These quantities should be adequate for about 42 h periodic swimming in an adult Nymphon.

Respiratory responses to air-exposure in the southern rock lobster, Jasus edwardsii (Hutton) (Decapoda:Palinuridae)

1997 ◽  
Vol 48 (8) ◽  
pp. 889 ◽  
Author(s):  
H. Harry Taylor ◽  
Francesca M. Waldron
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Base Excess ◽  
Respiratory Acidosis ◽  
Metabolic Cost ◽  
Excess Oxygen ◽  
Air Exposure ◽  
Water Oxygen ◽  
Jasus Edwardsii ◽  
Resting Metabolism

Air-exposure of settled Jasus edwardsii at 17˚C initially halved oxygen consumption, doubled ventilation frequency and reduced heart rate. During 8 h emersion, oxygen uptake partially recovered, ventilation remained elevated and heart rate was restored. Haemolymph PCO2 increased fourfold, despite the hyperventilation. Branchial gas exchange, initially impaired in air, may improve as the gills drain. Partial anaerobiosis was indicated by elevation of haemolymph [lactate-] to 4.2 mmol L-1. Although haemolymph pH decreased ~0.3 units over 8 h, a base excess compensated all of the metabolic and part of the respiratory acidosis. On return to water, oxygen consumption initially increased to >2.5 times pre-emersion rates while ventilation and heart rates increased further. Most respiratory variables returned to pre-emersion levels within 8 h of re- immersion, but oxygen consumption and heart rate remained elevated for 24 h. The excess oxygen consumption over resting rate during 24 h recovery in water indicated a metabolic cost of 8 h emersion equivalent to 10 h resting metabolism in water. These responses contrast with better acid–base compensation previously reported for undisturbed Homarus gammarus in air and worse tolerance of air-exposure by Panulirus argus

scholarly journals Adaptive Broadcasting Mechanism for Bandwidth Allocation in Mobile Services

2014 ◽  
Vol 2014 ◽  
pp. 1-14
Author(s):  
Gwo-Jiun Horng ◽  
Chi-Hsuan Wang ◽  
Chih-Lun Chou
Keyword(s):  
Analytical Model ◽  
Bandwidth Allocation ◽  
Data Dissemination ◽  
Data Access ◽  
Experimental Results ◽  
Bandwidth Utilization ◽  
Access Latency ◽  
The Mean ◽  
Access Efficiency ◽  
Broadcast Program

This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel’s bandwidth and the data channel’s bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

scholarly journals Metabolic cost of generating horizontal forces during human running

1999 ◽  
Vol 86 (5) ◽  
pp. 1657-1662 ◽  
Author(s):  
Young-Hui Chang ◽  
Rodger Kram
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Metabolic Cost ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Order Of Magnitude ◽  
Reaction Forces ◽  
The Cost ◽  
Support Body Weight ◽  
Human Running

Previous studies have suggested that generating vertical force on the ground to support body weight (BWt) is the major determinant of the metabolic cost of running. Because horizontal forces exerted on the ground are often an order of magnitude smaller than vertical forces, some have reasoned that they have negligible cost. Using applied horizontal forces (AHF; negative is impeding, positive is aiding) equal to −6, −3, 0, +3, +6, +9, +12, and +15% of BWt, we estimated the cost of generating horizontal forces while subjects were running at 3.3 m/s. We measured rates of oxygen consumption (V˙o 2) for eight subjects. We then used a force-measuring treadmill to measure ground reaction forces from another eight subjects. With an AHF of −6% BWt,V˙o 2 increased 30% compared with normal running, presumably because of the extra work involved. With an AHF of +15% BWt, the subjects exerted ∼70% less propulsive impulse and exhibited a 33% reduction inV˙o 2. Our data suggest that generating horizontal propulsive forces constitutes more than one-third of the total metabolic cost of normal running.

scholarly journals The cost of immunising at the general practice level

2009 ◽  
Vol 1 (4) ◽  
pp. 286 ◽  
Author(s):  
Nikki Turner ◽  
Paul Rouse ◽  
Stacey Airey ◽  
Helen Petousis-Harris
Keyword(s):  
General Practice ◽  
Cost Allocation ◽  
Cost Model ◽  
Cost Effective ◽  
Fee For Service ◽  
Activity Based Costing ◽  
Childhood Immunisation ◽  
Practice Nurses ◽  
The Mean ◽  
The Cost

INTRODUCTION: Childhood immunisation is one of the most cost-effective activities in health care. However, New Zealand (NZ) has failed to achieve national coverage targets. NZ general practice is the primary site of service delivery and is funded on a fee-for-service basis for delivery of immunisation events. AIM: To determine the average cost to a general practice of delivering childhood immunisation events and to develop a cost model for the typical practice. METHODS: A purposeful selection of 24 diverse practices provided data via questionnaires and a daily log over a week. Costs were modelled using activity-based costing. RESULTS: The mean time spent on an immunisation activity was 23.8 minutes, with 90.7% of all staff time provided by practice nurses. Only 2% of the total time recorded was spent on childhood immunisation opportunistic activities. Practice nurses spent 15% of their total work time on immunisation activity. The mean estimated cost per vaccination event was $25.90; however, there was considerable variability across practices. A ‘typical practice’ model was developed to better understand costs at different levels of activity. CONCLUSIONS: The current level of immunisation benefit subsidy is considerably lower than the cost of a standard vaccination event, although there is wide variability across practices. The costs of delivery exceeding the subsidy may be one reason why there is an apparently small amount of time spent on extra opportunistic activities and a barrier to increasing efforts to raise immunisation rates. KEYWORDS: Immunisation; vaccination; patient care management; cost analysis; cost allocation

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